Signaling- system



ourreo m lorries.

rnnn G. GARDNER. OF NEW- Yonmnl Y.. assmnon '10 west-mite mmmm com PANY. mconronarnn. OF NEW YORK. N. Y., A conrox'm'non'on new YORK.

smn'nnmo SYSTEM.

Specification. of Letters Jiatcnt.

. Patented: June '7, 1921.

Application filed November 21,1919. Serial No. 339,766.

To all ache/wit may cum-m)! Be itknown that 1, Farm G. (tannxnn, a citizen of the'linited States residing at Xew York. in the county of New York, State of NewYoi-k. have invented certain new and useful Improvements in Signaling Systems, of which the following-is a full, clear. concise. and exact description.

This invention relates to signaling systems and more specifically to signaling systents which are especially applicable to s gnaling on composite telegraph and telephone circuitsin certain telephone systems, particularl y those in which telegraph and telephone circuits are ttllltltlllttl. i1 is desirable to use for signaling purposes t'ttl'l'tIllH ol' ditlere-nt' l'retplcncles. lispcciully in cmnpnsil'c tclc graph and telephone systems it is dcsi rahle to use high l'requelncurrents nl' approximately 133! cycles per second for the purpose of operating a signal in t'tlllllt't'lltlll with the telephone service without interfering with the operation of the telegraph service. Since the standard type of signal used in connection with telephone lines is ada ited torespond only to a current of a much lower frequency, such asltig cycles per second. it is necessary to provide some means for translating the high frequenec current into a current of such low frequency as will properly operate the telephone signaling device.

In signaling systems of this nature now in use. it has been found t'easihle to employ-a translating means selectively responsive to the relatively high frequency currents transmittcd over the line. such means heing unrcs|mnsireto the relatively low I'requciu-y currents used for telegraphservice or impressed upon the line by the actuation of the switchhook on the connected telephone lines. However. it has llt"t'|l found omewhat dillicult to provide a telephone signaling device which is nnres mnsive to the currents of the latter mentioned elmracters. while remaining reliahly responsive to the translated currents. .\ltl1ough the desired result may he ohtained in a mrticular instance by means of accurate and refined adjustments of the signaling control device. such adjustments are very ditticult to ohtain as well as to maintain when once secured, since the electrical clmracteristies ot' the associated line circuit are unstahle.

The ohject of the present invention is to provide an improvedarrangement of this nature readily a )pli'eable to systems of this c-lmracter, in w llt'll the falseor improper operation of thetelephone signal control means is prevented.

' To obtain this object in accordance with a feature of the invention. the telephone signal control means is normally disassociated from the line circuit and is associated therewith only during the response of the translating means tothe current of the proper frequency when received 'over the line circuit.

*This and other features not specifically Inel'itititiml aliov'e. will more clearly appear from the l'ollowing s'pecilieation and the. accom mnying drawing in which the ligure. showsdiagrannnaticallv sullicient portions ol one end ol a telephone line circuit equipped with a portion of a composite ringer circuit and an associated link circuit to no aerly illustrate the invention.

in t 1e drawing. a telephone line circuit A. terminates in a jack hit a central ollice or switchlmaltl. Line conductors =1 and 5 of such line circuit may he assumed as extending to the line side of a regular composite circuitequipped with a composite ringer 'circuit. The complete composite ringer circuit is not shown since it is not essential to a proper understanding of the invention and may he of any suitahle type; A relay 6 l'n'idgetl across eotuluctors -l and of the outer section of the line circuitcontrols a relay h which controls a switching relay 7 for disconnecting the inner and outer sections ol the line circuit and for connecting the source of alternating current preferably of log-g cycles per second. to the Hillel section. The relay H also-controls a relay St for controlling the continuity of a hridge across the conductorsofsm-h inner section of the line circuit. lit-lay ltt included in such hridge is adapted to respond to the current supplied from the source connected to the inner section hy the relay 7 and controls the illumination of the line signal lamp 13. associated with thejack l. thronglrthe medium of a locking relay 1'1. link circuit B of any usual tvpe. equipped with a drop or other signaling device 3. bridged across the, conductors thereof. and terminating in a plug 2. is provided for connection with the jack l. sleeve relay ll. tl5 (lt'ltlttl with the line circuit is responsive to such interconnection to control another gap in the bridge circuit including the relay 10, and to render the line signal ineffective.

It is thought that the invention may be fully comprehended from the following description of the operation of the system shown on the drawln".

Assuming that the currenhihaving a frequency of approximately 133 cyc es per second, is being transmitted over the line con- (lllt'lul's l and 5 and flows throu i the windings of relay 6, relay 6, responding thereto, opens the circuit of and causes the release of normally operated relay 8. Relays 7 and 9 thereupon operate over a circuit extending from battery through the windings of relays 7 and fl in parallel to the normal contact of relay 8 and thence to ground. Relay 7, in operating, disconnects the conductors of the inner section ofthe line circuit extending to the jack 1, from the corresponding conductors 4 and 5 of the outer section extending to the distant station, and also connects to such inner section a source of si rnaling current of a frequencv of 165 cyc es per second, such as is usually employed in o Jerating telephonic signaling apparatus. e- ]ay 9, in operating over an obvious circuit, places the winding of relay 10 in bridged relation to the conductors of the inner section. Relay 10 operates over a circuit extending from the source of alternating current through the lower alternate contact of relay 7, the left-hand contact of relay 11, the contact of relay 9, the winding of relay 10 and the upper alternate contactof relay 7 to ground. Relav 12 then oaenatcs over an obvious circuit, the closure of its left-hand contact completing a locking circuit therefor and the closure of its right-hand contact cuusin" the illumination of the line lamp l3. fipon the cessation of the incoming signaling current present in the conductors 4 and 5, relay 6 releases, causing the rcoperation of relay 8 and the consequent release of relays T, 9 and 10. Thus the source of 16?; cycle alternating current is discomnectcd from the inner section of the line circuit. such section is reassociatcd with the outer section and the bridge including the relay 1 is again interrupted. However, line lamp 13 remains lighted due to the locked condition of relay 12.

In response to the illumination of lamp 13 the operator inserts plug 2 into jack 1. whereupon relay 11 operates over a circuit established from battery through the sleeve contacts of plug 2 and jack 1 and the winding of relay 11 to ground. The opening of the right-hand contact of relay ll releases relay 12 thereby extinguishing the line lamp 13. The left-hand contact of relay [1, in opening. introduces a second break in the bridge including the winding of ringing r'csponsc relay l0. 'lhcrefore in case ringing current-of 133' cycles per second is transmitted over the line conductors 4 and 5 while'the )lllg :2 remains in the jack 1 as in the case oi a recall from the distant station, relays 6,7, 8 and 9 function as before, but relay 10 does not respond due to the fact that the bridge therefor is opened at the left-hand contact of relay 11. Thus the drop or other telephonic signaling device ,3 associated with the connecting link circuit is operated over a circuit established from the source of alternatin current of 16?; cycles per second, throng the lower alternate contact of relay 7 the ring contacts of jack 1 and'the plug 2, the winding of the drop or other signaling device 3, the tip contacts of plug 2-and jack 1, and the u per alternate contact of relay/(to ground. on the removal of the plu r 2 from the jac 1, all the system restores to normal as shown in the drawing.

It will be evident that with the present invention the usual telephonic line signaling device is rendered independent of all signaling currents which may be received over the line circuit except those which cause the operation of the translating means.

What is claimed is:

1. In a signaling system a line circuit comprising innerand outer sections, means associated with the outer section and responsive to signaling cur-rent received thereover, means controlled thereby for disassociating the sections and connecting a source of signaling current to the inner section, additional means also controlled by the second mentioned means to associate with the inner section means responsive to current flowing from such source, and a signal controlled-thereby.

2. .In a signaling system a line circuit comprising inner and outer sections, a source of signaling current. a signal control-means responsive thereto. means for disassociating the sections andfor associating the source of current with the inner section, meansfor associating the signal control means with the inner section. and means associated with the outer section responsive to signaling current received thcreover for controlling the first and second mentioned means.

3. In a signalingsystem a line circuit, a source of current, means responsive thereto, a signaling device controlled thereby, and

means associated with the line circuit and responsive to signaling current received tiereover for simultaneously localizing a section of such line circuit and associating the source of current and the signal control means with such localized section.

4. In a signalingsystem a line circuit comprising normally interconnected inner and outer sections, a source of current, a signal control means responsive to current flowing therefrom, and means associated with the outer section and responsive to signaling current received thereover t0 disconnect the sections and to associate the source of current and the signal controlling means with the inner section and to restore the sections, the source of signaling current and the signal controlling means to normal upon the cessation of the current in the outer section.

5. In a signaling system a line circuit, a relay permanently associated therewith and responsive to periodically varying current of one frequency, a source of periodically varying current of another frequency, a seeand, relay responsive to current flowing therefrom for controlling a signaling device, a third relay for interrupting the continuity of the line circuit and associating the source with an isolated portion thereof, a fourth relay for associating the second relay with the isolated portion of the line circuit and a normally operated relay controlled by the first relay to simultaneously control the third and fourth relays.

In witness whereof, I hereunto subscribe my name this 18th day of November A. 1).,

FRED G. GARDNER. 

